JPH0418886Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an electronically controlled suspension device that suppresses roll (rolling) of a vehicle body.

[Technical background of the invention and its problems]

An electronically controlled suspension device has been proposed that improves riding comfort and handling stability by electronically controlling the damping force of a shock absorber and the spring reaction force of an air spring chamber. In automobiles equipped with such electronically controlled suspension devices, it is desired to improve ride comfort and steering stability by suppressing vehicle body roll. Therefore, for example, when the steering wheel is turned beyond the neutral range, the communication valve that communicates between the left and right air spring chambers is shut off to increase the spring reaction force on the sinking side and reduce the spring reaction force on the other side. Devices that perform control to reduce rolls have been considered. In such a device, when the steering wheel angle is returned to the neutral range, the communication valve is opened to communicate the left and right air spring chambers, thereby canceling the roll control. However, immediately after the steering wheel is suddenly returned to the neutral range, lateral acceleration remains.
If the communication valve was opened in this condition, the roll would be exacerbated, resulting in poor ride comfort.

[Purpose of invention]

The present invention was developed in view of the above points, and its purpose is to shut off the communication valve that communicates between the left and right fluid spring chambers when the roll displacement of the vehicle body is predicted or detected, and to prevent the fluid springs on the sinking side from communicating with each other. In a suspension device that performs roll control by supplying a set amount of fluid to a chamber and discharging a set amount of fluid from a fluid spring chamber on the floating side, this is to prevent ride comfort from worsening when the steering wheel is returned to the neutral range. The purpose of the present invention is to provide an electronically controlled suspension device that provides a controlled suspension system.

[Summary of the idea]

The present invention includes a fluid spring chamber interposed between a wheel and a vehicle body provided for each wheel, a fluid supply/discharge device for controlling supply and discharge of fluid in the fluid spring chamber, and a fluid supply/discharge device for controlling the supply and discharge of fluid in the fluid spring chamber. a communication control means for controlling a communication state between a spring chamber and the fluid spring chamber on the right wheel side; a steering sensor for detecting a steering state; and a communication means for detecting a turning state of the vehicle based on an output of the steering sensor. The communication control means is switched to a non-communicating state, and roll control is performed to supply fluid to the fluid spring chamber on the outside of the turn and to discharge fluid from the fluid spring chamber on the inside of the turn in accordance with the control target determined according to the output of the steering sensor. The suspension device is equipped with an acceleration sensor that detects acceleration in the left and right direction acting on the vehicle body, and the roll control means detects the acceleration that is detected by the steering sensor after the roll control is executed. The electronic control is characterized in that when the steering angle is within a set neutral range and the lateral acceleration detected by the steering sensor is below a set value, a return control is executed to switch the communication control means to a communication state. It is a suspension device.

[Example of idea]

Hereinafter, an electronically controlled suspension device according to an embodiment of the invention will be described with reference to the drawings. In Figure 1, S _FR indicates a suspension unit for the right front wheel of a car, S _FL indicates a suspension unit for the left front wheel, S _RR indicates a suspension unit for the right rear wheel, and S _RL indicates a suspension unit for the left rear wheel. ing. The suspension units S _FR , S _FL , S _RR , and S _RL have main air spring chambers 11a to 11d, sub air spring chambers 12a to 12d, and
It is composed of shock absorbers 13a to 13d and a coil spring (not shown) used as an auxiliary spring. Further, 15a to 15d are switching devices for switching the damping force of the shock absorbers 13a to 13d to hard or soft.
The switching devices 15a to 15d are controlled by the controller 16. In addition, 17a-1
7d are bellows.

Furthermore, a compressor 18 compresses the atmospheric air sent from an air cleaner (not shown) and supplies it to the dryer 19. This dryer 19 dries the supplied compressed air using silica gel or the like. The compressed air from the dryer 19 is stored in a front wheel reserve tank 20F and a rear wheel reserve tank 20R via a pipe A, respectively.
Reference numeral 21 denotes a pressure sensor provided in the reserve tank 20F. When the internal pressure of the reserve tank 20F decreases to a set value or less, a signal from the pressure sensor 21 causes the compressor 18 to operate.
When the internal pressure of the reserve tank 20F becomes equal to or higher than the set pressure, the compressor 18 is stopped by a signal from the pressure sensor 21.

Further, the reserve tank 20F and the main air spring chamber 11a are connected to the reserve tank 20F and the main air spring chamber 11b via the air supply solenoid valve 22a.
are connected via the air supply solenoid valve 22b. Furthermore, the reserve tank 20R and the main air spring chamber 11c are connected to an air supply solenoid valve 22c.
The reserve tank 20R and the main air spring chamber 11d are connected via an air supply solenoid valve 22d. The above solenoid valves 22a to 22
d is a valve that is always closed.

Further, the compressed air in the main air spring chamber 11a passes through the exhaust solenoid valve 23a, the compressed air in the main air spring chamber 11b passes through the exhaust solenoid valve 23b, and the compressed air in the main air spring chamber 11c passes through the exhaust solenoid valve 23a. The compressed air in the main air spring chamber 11d is released to the atmosphere via the exhaust solenoid valve 23c and an exhaust pipe (not shown). The solenoid valves 23a to 23d are valves that are always closed.

Furthermore, the main air spring chamber 11a and the auxiliary air spring chamber 12a each have a spring constant switching solenoid valve 26.
The main air spring chamber 11b and the auxiliary air spring chamber 12b are connected to a spring constant switching solenoid valve 2 via a.
6b, the main air spring chamber 11c and the auxiliary air spring chamber 12c are connected to the spring constant switching solenoid valve 26c, and the main air spring chamber 11d and the auxiliary air spring chamber 12d are connected to the spring constant switching solenoid valve 26d. are connected to each other via

Furthermore, the main air spring chambers 11a and 11b are connected to the communication pipe B.
The main air spring chambers 11c and 11d are connected via the communication pipe C and the communication solenoid valve 27R. The communication solenoid valves 27F and 27R are valves that are always open.

By the way, the above solenoid valves 22a to 22
d, 23a-23d, 26a-26d, 27F,
Opening/closing control of 27R is performed by signals from the controller 16.

Furthermore, 30 is a steering sensor that detects the steering angle of the steering wheel, 31 is a brake sensor that detects on/off of the brake, 32 is an accelerator opening sensor that detects the opening of the accelerator, and 33 is a steering sensor that detects the steering angle of the steering wheel, 33 is an accelerator opening sensor that detects the opening of the accelerator, and 33 is a steering sensor that detects the steering angle of the steering wheel. An acceleration sensor that detects acceleration, 34 a vehicle speed sensor that detects vehicle speed, 35 a front vehicle height sensor that detects the height of the front part (front wheel part) of the car, and 36 a rear part (rear wheel part) of the car.
This is a rear vehicle height sensor that detects the vehicle height of the vehicle. Signals from the sensors 30 to 36 are supplied to the controller 16.

Next, control of an embodiment of the invention constructed as described above will be explained with reference to the flowchart of FIG. When the ignition key is turned on, the controller 16 starts the operation of the flowchart shown in FIG. First, in step S1, a predetermined memory area in the controller 16 that stores the steering wheel angle and vehicle speed is cleared to zero.
Next, the process proceeds to step S2, where the map memory T _M is reset (T _M =0). The process then proceeds to step S3, where the controller 16 confirms that the communication solenoid valves 27F and 27R are open. Further, the process proceeds to step S4, where the steering wheel angle detected by the steering sensor 30 is input to the controller 16, and this steering wheel angle is read. Furthermore, vehicle speed sensor 3
The vehicle speed detected at step 4 is input to the controller 16. Then, the process proceeds to step S5, where it is determined whether the above-mentioned steering wheel angle is within the neutral range. Here, the fact that the steering wheel angle is in the neutral range means that the steering wheel is not being steered to the right or left by a predetermined angle or more. "YES" in this step S5
If it is determined that this is the case, the process advances to step S6. In this step S6, it is determined whether the acceleration G in the lateral (left and right) direction detected by the acceleration sensor 33 is less than or equal to a set value _G0 . "YES" in this step S6
If it is determined that this is the case, the process advances to step S7. In this step S7, the air supply solenoid valves 22a-
22d and exhaust solenoid valves 23a to 23
The controller 16 confirms whether d is closed. On the other hand, "NO" in step S6 above.
If it is determined that this is the case, the process returns to step S4.

On the other hand, if the determination in step S5 is "NO", the process proceeds to step S8 and subsequent steps for performing roll control. First, in step S8, the communication solenoid valves 27F and 27R are closed under the control of the controller 16. Then, in the next step S9, the control time T _P , that is, the time to open the solenoid valve, is determined from the vehicle speed-steering wheel angle map shown in FIG. 3 based on the above-mentioned steering wheel angle and vehicle speed. This control time T _P is determined by the area I~ of the vehicle speed-steering wheel angle map in Figure 3, and these areas I~ approximately correspond to the magnitude of the lateral acceleration acting on the vehicle body determined by the vehicle speed and steering angle. They are divided into corresponding sections, and the control time T _P is written in brackets. When the process in step S9 is completed, the process proceeds to step S10, where the control time T (=T _P -T _M ) is calculated.
is calculated. Then, the process proceeds to step S11, where it is determined whether "T>0" or "T≦0". If it is determined in step S11 that "T≦0", the process returns to step S4. That is, in this case, vehicle body attitude control is not performed. On the other hand, if it is determined in step S11 that "T>0", the process advances to step S12. In this step S11, based on the control time T, the air supply solenoid valves 22a to 22d and the exhaust solenoid valve 2 are
3a to 23d are controlled to open and close to control the vehicle body attitude. For example, when the steering wheel is turned to the right, the air supply solenoid valves 22b and 2 for the left wheel are
2d is opened for the control time T under the control of the controller 16, and the main air spring chambers 11b and 11d are opened.
compressed air is supplied to the As a result, the vehicle height of the left wheel is biased in a direction higher than before the air supply. Furthermore, the exhaust solenoid valve 2 for the right wheel
3a and 23c are opened for the control time T under the control of the controller 16, and the compressed air in the main air spring chambers 11a and 11c for the right wheel is released to the atmosphere. As a result, the vehicle height of the right wheel is biased in a direction lower than before the release. In other words, when the steering wheel is turned to the right, the vehicle height of the left wheel is lowered, the vehicle height of the right wheel is prevented from increasing, and roll displacement of the vehicle body is suppressed.

When the process of step S12 is completed, the process advances to step S13, where the map memory is updated.
That is, T _P is set to T _M and the process returns to step S4. Therefore, if the turning is continued in the same area of the vehicle speed-handle angle map, or if the turning is continued in an area of the same map where the control time is smaller, the control time T _P found in step S9 is Since it is the same as or smaller than T _M already stored in the map memory, the control time T≦0 in step S10,
The process returns from step S11 to step S4. Then, when the vehicle shifts from turning to straight-ahead travel, it is determined in step S5 to be ``YES'', and in step S7, when it is determined that the lateral acceleration G is less than the set value _G0 , each air supply solenoid is activated in step S7. After confirming that the valve and each exhaust solenoid valve are closed, the communication solenoid valves 27F and 27R are opened in step S3 after passing through step S2, and the left and right air spring chambers are maintained at the same pressure.
Furthermore, if the vehicle speed-handle angle map changes to a larger control time region during turning, the control time T _P determined in step S9 is the control time already stored in the map memory. Since it is larger than T _M , step S10
Control time T (= T _P − T _M ) that needs to be added in
is determined, and control for the control time T is commanded in step S12.

[Effect of idea]

As detailed above, according to the present invention, when the roll displacement of the vehicle body is predicted or detected, the communication valve that communicates between the left and right fluid spring chambers is shut off, and a set amount of fluid is supplied to the sinking side fluid spring chamber. In a suspension device that performs roll control by supplying fluid and discharging a set amount of fluid from the fluid spring chamber on the floating side, after the roll control described above, the steering wheel angle is in the neutral range and the lateral acceleration is below the set value. Since the communication valve is opened for the first time to restore the roll control, the roll control is not promoted at the time of restoration, and it is possible to provide an electronically controlled suspension device that can improve riding comfort.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an electronically controlled suspension system according to an embodiment of the invention, FIG. 2 is a flowchart showing the operation of the embodiment, and FIG. 3 is a diagram showing a vehicle speed-handle angle map. 11a-11d...main air spring chamber, 12a-1
2d...Sub-air spring chamber, 16...Controller,
22a to 22d... Air supply solenoid valve, 2
3a to 23d...Exhaust solenoid valve, 27
F, 27R...Communication solenoid valve.

Claims (1)

[Scope of utility model registration request] A fluid spring chamber interposed between the wheel and the vehicle body provided for each wheel, a fluid supply and discharge device that controls the supply and discharge of fluid in the fluid spring chamber, and the fluid spring chamber on the left wheel side and the right a communication control means for controlling a state of communication with the fluid spring chamber on the wheel side; a steering sensor for detecting a steering state; and a communication control means for the communication means when a turning state of the vehicle is detected based on the output of the steering sensor. A roll control system that executes roll control in which fluid is switched to a non-communicating state and fluid is supplied to the fluid spring chamber on the outside of the turn and fluid is discharged from the fluid spring chamber on the inside of the turn in accordance with the control target determined according to the output of the steering sensor. The suspension device includes an acceleration sensor for detecting acceleration in the left and right direction acting on the vehicle body, and the roll control means includes:
After execution of the roll control, when the steering angle detected by the steering sensor falls within the set neutral range and the lateral acceleration detected by the acceleration sensor falls below the set value, the communication control means is brought into communication. An electronically controlled suspension device characterized by executing return control for switching.